For a valve mounted on a piping system that supplies gas to semiconductor manufacturing equipment or the like, it is necessary to prevent formation of dew condensation within the valve due to a temperature drop in the gas as it passes through the valve. In addition, a valve mounted on a piping system that carries liquid that solidifies at a temperature near room temperature, it is necessary to prevent a blockage of the valve or development of accretion within the valve due to solidification of the liquid. Still further, for a piping system that carries high temperature gas or liquid, a temperature drop in the fluid to be carried through the piping system as the fluid passes through the valve is a problem when the fluid needs to be carried through the piping system without any appreciable temperature drop.
In order to prevent these problems, different types of heating mechanisms, which are built in or attached to a fluid valve, for heating the area within the valve where the fluid passes and the like have been proposed as described, for example, in Japanese Unexamined Patent Publication No. 7 (1995)-71648, Japanese Unexamined Patent Publication No. 2001-349486, and PCT Japanese Publication No. 10(1998)-502995.
The problem of dew condensation, development of accretion and the like, however, may occur not only in the valve section but also in the joint sections connecting the valve to a piping system. The conventional valve heating mechanisms, however, are either built in the valve or mounted only on the valve. Consequently, heretofore, additional heaters have been required for mounting on the join sections.
The situation in which separate heating mechanisms are required for the valve and joint sections creates a problem of unequal heating between the flow paths within the valve and joints, as well as problems of increased cost and complicated configuration of the piping system.
In view of the circumstances described above, it is an object of the present invention to provide a heating mechanism capable of heating not only a valve connected to a fluid piping system through joints but also the joints integrally and uniformly.